<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>js练习</title>
    <script src="https://code.jquery.com/jquery-3.7.1.min.js" integrity="sha256-/JqT3SQfawRcv/BIHPThkBvs0OEvtFFmqPF/lYI/Cxo=" crossorigin="anonymous"></script>
</head>
<body>
    <script>
        // let ret;
        // console.log(typeof ret);
        // ret = null;
        // console.log(typeof ret); 
        // let arr = [];
        // console.log(arr);
        // arr[0] = 1;
        // arr[1] = "String";
        // console.log(arr);
        // function add(x, y) {
        //     return x+y;
        // }
        // function add2(x, y) {
        //     console.log(x + y);
        //     return;
        // }
        // let a = add2(10);
        // let a = add2(10,20,30);
        // let aa = function(x, y) {
        //     console.log(x + y);;
        // }
        // console.log(typeof aa);
        // aa(10, 20);

        let a = {
            "age" : 15,
            "gender" : "male" 
        };
        let b = new Object();
        a.name = "张三";
        b.name = "李四";
        console.log(a);
        console.log(b);
        b["age"] = 16;
        b["gender"] = "male";
    </script>
</body>
</html>